From mboxrd@z Thu Jan 1 00:00:00 1970 From: Glauber de Oliveira Costa Subject: Re: include files for kvmclock Date: Wed, 07 Nov 2007 11:16:34 -0200 Message-ID: <4731BAB2.9040004@redhat.com> References: <11943875362987-git-send-email-gcosta@redhat.com> <11943875433821-git-send-email-gcosta@redhat.com> <1DC8211684B62Btakebe_akio@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, jeremy-TSDbQ3PG+2Y@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, hollisb-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org, avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org To: Akio Takebe Return-path: In-Reply-To: <1DC8211684B62Btakebe_akio-+CUm20s59erQFUHtdCDX3A@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Akio Takebe escreveu: > Hi, Glauber > > This is interesting facility. :-) > >> +#define KVM_HCALL_REGISTER_CLOCK 1 >> + >> +union kvm_hv_clock { >> + struct { >> + u64 tsc_mult; >> + u64 now_ns; >> + /* That's the wall clock, not the water closet */ >> + u64 wc_sec; >> + u64 wc_nsec; >> + u64 last_tsc; >> + /* At first, we could use the tsc value as a marker, but Jeremy >> + * well noted that it will cause us locking problems in 32-bit >> + * sys, so we have a special version field */ >> + u32 version; >> + }; >> + char page_align[PAGE_SIZE]; >> +}; >> + > Why does kvm_hv_clock need page_align? Each vcpu will register a page on its own. In the guest side, it will be an array of pages. So, we make it page sized. > And also the kvm_hv_clock is alloced with kvm_vcpu, There's no requirements on the host part at all. So it doesn't really matter. In the next version, I may make it even a simple pointer. > so the align is not enough, isn't it? > I thik __atribute__((__aligne__(PAGE_SIZE)))) is better than it. It deals with the start of the structure, but not with its size. See the guest part: Where it matters, I do use it. Thanks -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (GNU/Linux) Comment: Using GnuPG with Remi - http://enigmail.mozdev.org iD8DBQFHMbqyjYI8LaFUWXMRAgfOAKCTeKF3cWbhILYSXY+MjtXo8B87EwCeNNhn z9RDYaCWHIxsqlciMF0i27w= =EIEM -----END PGP SIGNATURE----- ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/